Catalytic conversion of ethanol and methanol to an isobutanol-containing reaction product using a thermally decomposed hydrotalcite containing the anion of ethylenediaminetetraacetic acid

ABSTRACT

Hydrotalcites containing the anion of ethylenediaminetetraacetic acid are partially or fully thermally decomposed to provide catalysts useful for the conversion of ethanol and methanol to a reaction product comprising isobutanol.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims benefit of priority from Provisional ApplicationNo. 60/965,728, filed Aug. 22, 2007. This application relates tocommonly-assigned applications filed concurrently on Aug. 22, 2008.

FIELD OF THE INVENTION

The present invention relates to the catalytic conversion of ethanolplus methanol to an isobutanol-containing reaction product. Variousorganic chemicals, including isobutanol itself, can be separated fromthe reaction product. The catalysts are hydrotalcites, optionallycontaining transition metals, that contain the anion ofethylenediaminetetraacetic acid, that have been thermally decomposed,either partially or fully, to form catalytically active species.

BACKGROUND

Efforts directed at improving air quality and increasing energyproduction from renewable resources have resulted in renewed interest inalternative fuels, such as ethanol and butanol, that might replacegasoline and diesel fuel, or be used as additives in gasoline and dieselfuel.

Methods for producing isobutanol from methanol and other alcohols,particularly ethanol, are known. It is known that isobutanol can beprepared by condensation of ethanol and methanol over basic catalysts athigh temperature using the so-called “Guerbet Reaction.” See forexample, J. Logsdon in Kirk-Othmer Encyclopedia of Chemical Technology,John Wiley and Sons, Inc., New York, 2001.

In addition, U.S. Pat. No. 5,300,695, assigned to Amoco Corp., disclosesprocesses in which an alcohol having X carbon atoms is reacted over anL-type zeolite catalyst to produce a higher molecular weight alcohol. Insome embodiments, a first alcohol having X carbon atoms is condensedwith a second alcohol having Y carbon atoms to produce an alcohol havingX+Y carbons. In one specific embodiment, ethanol and methanol are usedto produce isobutanol using a potassium L-type zeolite.

J. I. DiCosimo, et al., in Journal of Catalysis (2000), 190(2), 261-275,describe the effect of composition and surface properties onalcohol-coupling reactions using Mg_(y)AlO_(x) catalysts for alcoholreactions.

Carlini et al. describe a catalytic reaction of methanol with n-propanolto produce isobutyl alcohol. The involved catalyst is a calcinedhydrotalcite in combination with copper chromite. See C. Carlini et al,Journal of Molecular Catalysis A: Chemical (2005), 232 (1-2) 13-20. Seealso C. Carlini, Journal of Molecular Catalysis A: Chemical (2004), 220(2), 215-220, in which the catalyst is a mixture of a hydrotalcite withpalladium, nickel, rhodium or copper, with the mixture being calcined at500° C.

Hydrotalcites are layered, double hydroxides of the general formula(M²⁺ _(1−x)M³⁺ _(x)(OH)₂)(A^(n−) _(x/n)).yH₂OThe M²⁺ ions can be a variety of divalent cations (e.g., Mg, Ni, Pt, Pd,Zn, Co, Fe, Cu) and the M³⁺ ions can be trivalent Al, Fe or Cr. Somehydrotalcites are described by V. K. Diez, C. R. Apesteguia, and J. I.DiCosimo (Latin American Applied Research, 33, 79-86 (2003)) and N. N.Das and S. C. Srivastava (Bull. Mater. Sci. 25, (4), 283-289 (2002)).

It has been found that partially or fully thermally decomposedhydrotalcites that incorporate the anion of ethylenediaminetetraaceticacid, can yield catalysts that are effective for the conversion ofethanol plus methanol to a reaction product that comprises (i.e.,contains among other things) isobutanol.

SUMMARY OF THE INVENTION

Certain hydrotalcites, as described herein, are partially or fullythermally decomposed to provide catalysts useful for the conversion ofethanol plus methanol to an isobutanol-containing reaction product.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 shows a typical powder X-ray diffraction pattern of thehydrotalcite material of Example 1 before calcination, and indicatesreflections typical of a hydrotalcite phase.

FIG. 2 shows a powder X-ray diffraction pattern of the material of FIG.1 after calcination, showing decomposition of the hydrotalcite phase bythe substantial loss of those reflections that are typical of ahydrotalcite phase.

DESCRIPTION

A vapor stream comprising ethanol and methanol (that may contain somewater, and may be diluted with an inert gas such as nitrogen and carbondioxide) is contacted with at least one thermally decomposedhydrotalcite catalyst that incorporates the anion ofethylenediaminetetraacetic acid at a temperature and pressure sufficientto produce a reaction product comprising water, unreacted ethanol and/ormethanol (if less than complete conversion of ethanol and/or methanol),and isobutanol. Butanols other than isobutanol, higher alcohols (higherin the sense that they contain more than 4 carbon atoms) and otherorganic species may also be produced. Suitable temperatures are in therange of about 150° C. to about 500° C., for example about 200° C. toabout 500° C. Suitable pressures are from about 0.1 MPa to about 20.7MPa. To optimize the production of isobutanol over other organicproducts, it is preferred that methanol and ethanol are used at a molarratio of at least about 2 to 1.

The catalysts that are useful in the present invention are partially orfully thermally decomposed hydrotalcites of the empirical formula (priorto thermal decomposition):[M²⁺ _(1−x)M³⁺ _(x)(OH)₂][{(M′A′)^(n′−}) _(a)A^(n−) _((1−a)(n′/n)]x/n′).yH₂Owherein

-   M²⁺ is divalent Mg, or a combination of divalent Mg and at least one    divalent member selected from the group consisting of Zn, Ni, Pd,    Pt, Co, Fe, and Cu;-   M³⁺ is trivalent Al, or a combination of trivalent Al and at least    one trivalent member selected from the group consisting of Fe and    Cr;-   x is 0.66 to 0.1;-   M′ is (i) one or more divalent members selected from the group    consisting of Zn, Ni, Pd, Pt, Fe, Co, and Cu; or (ii) one or more    trivalent members selected from the group consisting of Fe, Cr, and    Ru; or (iii) a mixture of one or more of said divalent members with    one or more of said trivalent members;-   A′ is the anion of ethylenediaminetetraacetic acid;-   n′ is the absolute value of the sum of the oxidation state of M′    (i.e., +2 if M′ is one or more divalent members or +3 if M′ is one    or more trivalent members) and the oxidation state of the anion of    ethylenediaminetetraacetic acid (−4) (for example, for M′A′ wherein    M′ is Zn²⁺ with an oxidation state of +2, n′ is +2); provided that    if M′ is said mixture, then n′ is calculated according to the    following equation:    n′=the absolute value of [X _(D)(2)+X _(D)(−4)+X _(T)(3)+X    _(T)(−4)], wherein-   X_(D)=the sum of the number of moles of all divalent members divided    by (the sum of the number of moles of all divalent members+the sum    of the number of moles of all trivalent members), and-   X_(T)=the sum of the number of moles of all trivalent members    divided by (the sum of the number of moles of all divalent    members+the sum of the number of moles of all trivalent members);-   A^(n−) is CO₃ ²⁻(n=2) or OH⁻ (n=1);-   a=0.001 to 1; and-   y=0 to 4.

In a preferred embodiment, M²⁺ is divalent Mg; M³⁺ is trivalent Al; M′is Co, Cr, Cu or Ni; a is 0.01 to 0.44; and A^(n−) is CO₃ ²⁻ (n=2) orOH⁻ (n=1).

Without wishing to be bound by theory, it is believed that thehydrotalcites of the above formula have the species M′A′ intercalatedinto a hydrotalcite structure.

The catalysts that are useful in the present invention are derived froma hydrotalcite of the formula as defined above by a process comprisingheating the hydrotalcite for a time and at a temperature sufficient tocause a diminution in the hydrotalcite powder X-ray diffraction patternpeak intensities between 2θ angles of 10 degrees and 70 degrees usingCuKα radiation.

Catalysts derived from the hydrotalcite can be synthesized by thefollowing preferred method. A first aqueous solution containing M′A′ isprepared. The solution can be prepared by addingethylenediaminetetraacetic acid (EDTA) to water, adding hydroxide(preferably NaOH) until the EDTA is dissolved in the water, followed byadding an M′ salt, preferably a nitrate, chloride or acetate salt. Mostpreferred are nitrate salts. Sodium, potassium or ammonium hydroxide isthen added until a pH of about 10 is reached. The solution is thenwarmed to a temperature of about 60° C. to 70° C., preferably 65° C.Next, a second aqueous solution of M²⁺ and M³⁺ salts is prepared bydissolving the salts in water. The second solution containing the M²⁺and M³⁺ salts is added drop-wise to the first solution. Alternatively, aplurality of individual metal salt solutions may be used, provided thatthey are added concurrently to the solution containing EDTA and the M′salt. The resulting suspension is warmed to a temperature of about 60°C. to 70° C., preferably 65° C. During the addition of the secondsolution to the first solution, the pH of the resulting suspension ismonitored and adjusted, if necessary, to maintain a pH of about 10 usinghydroxide (with soluble metal carbonate or bicarbonate if A^(n−) ischosen to be CO₃ ²⁻).

The resulting suspension (i.e., a precipitate suspended in a liquid) canbe aged, preferably for approximately 18 hours, at 60° C. to 70° C. Theprecipitate is then separated, generally by filtering, and subsequentlydried (generally in a vacuum oven or in air). The dried precipitate canbe analyzed by powder X-ray diffraction to confirm the presence of ahydrotalcite phase. This phase is isostructural with the hydrotalciteMg₆ Al₂(CO₃)(OH)₁₆.4H₂O (JCPDS card # 54-1030; Powder Diffraction Files,International Centre for Diffraction Data, 1601 Park Lane, Swarthmore,Pa. 19081). The dried precipitate is then calcined by heating it for atime and at a temperature sufficient to cause a diminution in thehydrotalcite powder X-ray diffraction pattern peak intensities between2θ angles of 10 degrees and 70 degrees using CuKα radiation. Thecalcined material can be analyzed by powder X-ray diffraction to confirmthe diminution (including the complete absence) in these peakintensities and the appearance of new peaks corresponding to a materialwhich is isostructural with partially crystalline magnesium oxide (MgO,JCPDS card # 65-0476). It is preferred to calcine the dried precipitatefor a time and at a temperature sufficient to substantially reduce thepeak intensities characteristic of the hydrotalcite phase.

Although any calcination protocol can be used, one that is particularlyuseful on a laboratory scale includes heating the hydrotalcite in a oneinch (2.5 cm) diameter tube furnace from about 25° C. to 360° C. over140 minutes at 2.4° C. per minute, and then holding at 360° C. for about2 to about 4 hours.

The catalysts usable in the process of the invention can be prepared asdescribed above. The catalysts may be used in the form of powders,granules, or other particulate forms. Selection of an optimal averageparticle size for the catalyst will depend upon such process parametersas reactor residence time and desired reactor flow rates.

The catalytic conversion of ethanol plus methanol to the reactionproduct comprising isobutanol can be run in either batch or continuousmode as described, for example, in H. Scott Fogler, (Elements ofChemical Reaction Engineering, 2^(nd) Edition, (1992) Prentice-Hall Inc,CA). Suitable reactors include fixed-bed, adiabatic, fluid-bed,transport bed, and moving bed.

It is preferable, but not essential, to treat the catalyst, prior to itsuse, with nitrogen or air at elevated temperatures, which is thought toremove unwanted carbonates from the catalyst surface. If the startinghydrotalcite contains nickel, palladium, platinum, cobalt or copper, itis also preferred, but not essential, to treat the catalyst, prior toits use, with hydrogen at elevated temperatures. One protocol that hasbeen found to be effective is described in more detail in Example 1,below. If catalyst treatment is desired, the catalyst may be treated insitu in the reactor or ex situ and then introduced into the reactor.

During the course of the reaction, the catalyst may become fouled, andtherefore it may be necessary to regenerate the catalyst. Preferredmethods of catalyst regeneration include, contacting the catalyst with agas such as, but not limited to, air, steam, hydrogen, nitrogen orcombinations thereof, at an elevated temperature, although care must betaken not to use a temperature that is so high that the regenerationresults in a loss of surface area or other unwanted effects. If catalystregeneration is desired, the catalyst may be regenerated in situ in thereactor or ex situ and then introduced into the reactor.

One skilled in the art will know that conditions, such as temperature,catalytic metal, catalyst support, reactor configuration and time canaffect the reaction kinetics, product yield and product selectivity.Standard experimentation can be used to optimize the yield of isobutanolfrom the reaction.

Isobutanol can be separated from the reaction product by known chemicalengineering methods, including distillation. Other specific chemicals(or combinations of chemicals) also can be removed from the reactionproduct using known chemical engineering methods. The specific methodswill be dependent on the nature of the reaction product, which, in turn,is dependent on the specific catalyst used and the reaction conditions,particularly the extent of conversion of ethanol and methanol.

Although particular embodiments of the present invention have beendescribed in the foregoing description, it will be understood by thoseskilled in the art that the invention is capable of numerousmodifications, substitutions, and rearrangements without departing fromthe spirit or essential attributes of the invention.

EXAMPLES Example 1 [M²⁺ _(1−x)M³⁺ _(x)(OH)₂][{(M′A′)_(n−)}_(a)A^(n−)_((1−a)(n′/n))]_(x/n′).yH₂OM²⁺ is Mg; M³⁺ is Al; x=0.25; a=0.44; A′=theanion of ethylenediaminetetraacetic acid; M′=Co; A^(n−)=OH⁻; n′=2; n=1

11.09 g of ethylenediaminetetraacetic acid (Sigma-Aldrich, St. Louis,Mo.) was dissolved in 250 milliliters (ml) of water in a three neck,round bottom flask and heated to 65° C. Enough sodium hydroxide (2 MNaOH solution (Mallinckrodt Baker, Phillipsburg, N.J.)) was added tocompletely dissolve the EDTA. 4.8 g of cobalt nitrate Co(NO₃)₂.6H₂O(Alfa Aesar, Ward Hill, Mass.) was then dissolved in the preheatedsolution containing EDTA. Following the addition of cobalt nitrate, thepH was adjusted to about 10 by adding 2 M NaOH solution (MallinckrodtBaker). Separate solutions of aluminum nitrate and magnesium nitratewere prepared as follows: 27.5 g of aluminum nitrate (Al(NO₃)₃.9H₂O (EMDSciences, Gibbstown, N.J., AX0705-11)), and 57.6 g of magnesium nitrate(Mg(NO₃)₂.6H₂O (EMD Sciences, MX0060-1)) were each dissolved in 100 mlof water, and the two solutions were added drop-wise (concurrently) tothe preheated solution containing EDTA and cobalt. The time for thisaddition was about 45 minutes. During this addition, sodium hydroxidesolution was added to maintain a pH of about 10. The preheated solutionwas stirred during the addition of the metal nitrates. After completeaddition of these metal nitrates, the resulting suspension was kept at65° C. with stirring for 1 hour and then aged at this temperature for 18hours without stirring. The precipitate was separated from solution byfiltering. The synthesized separated solids were dried in vacuum oven at90° C. for 48 hours and calcined at 360° C. for 2 hours in nitrogen. Theheating protocol was as follows: the precipitate was placed in a 1 inchdiameter tube furnace, and the temperature was increased from 25° C. to360° C. at 2.4° C. per minute over the course of 140 minutes, followedby 360° C. for 2 hours. The catalyst was evaluated according to thefollowing procedure.

Reactor Evaluation

Approximately 2 cubic centimeters (cc) of catalyst was loaded on astainless steel mesh support within a 18 inch×½ inch (45.7 cm×1.3 cm)outside diameter (o.d.) type 360 stainless steel tube reactor withinlets for gas and liquid feeds. The catalyst was then pre-conditionedin situ in the reactor by flowing nitrogen gas, initially at roomtemperature, raising the temperature to 350° C., holding it there forone hour, lowering the temperature to 180° C., flowing hydrogen gas at15 cc/min for one hour, and reintroducing nitrogen gas at a flow rate of15 cc/min. The reactor temperature was increased to 300° C., and a mixedstream of methanol and ethanol at a weight ratio of 5 to 1 wasintroduced. At reaction temperature nitrogen flow was set at 15 cc/minand the flow of the mixed stream of methanol and ethanol was set at 1.03ml/hr. After 60 minutes, reaction off-gases were condensed over a fiveminute period into cold N-methylpyrrolidone, and the resultant solutionwas analyzed using an Agilent™ 5890 GC (Palo Alto, Calif.) equipped withflame ionization and mass selective detectors. Results are shown inTable 1, wherein “EtOH” means ethanol, “i-BuOH” means isobutanol,“Conv.” means conversion, and “Sel.” means selectivity. Ethanolconversion (%) was calculated as follows: [(1−carbon moles of unreactedethanol)/carbon moles of total outlet gases] times 100. Selectivity (%)was calculated as follows: (moles of i-BuOH/moles of ethanol reacted)times 100.

TABLE 1 Temp. EtOH i-BuOH ° C. Minutes Conv. Sel. 300 60 61.9 6.7 350 6067.8 10.8 400 60 82.7 13.5

Example 2 [M²⁺ _(1−x)M³⁺ _(x)(OH)₂][{(M′A′)^(n′−)}_(a)A^(n−)_((1−a)(n′/n))]_(x/n′).yH₂O M²⁺ is Mg; M³⁺ is Al; x=0.25; a=0.44; A′ isthe anion of ethylenediaminetetraacetic acid; M′=Ni; A^(n−)=OH⁻; n′=2;n=1

11.09 g of ethylenediaminetetraacetic acid (Sigma-Aldrich) was dissolvedin 250 ml of water in a three neck, round bottom flask and heated to 65°C. Enough sodium hydroxide (2 M NaOH solution (Mallinckrodt Baker)) wasadded to completely dissolve the EDTA. 4.8 g of nickel nitrate(Ni(NO₃)₂.6H₂O (Sigma-Aldrich)) was then dissolved in the preheatedsolution containing the EDTA. Following the addition of nickel nitrate,the pH was adjusted to about 10 by adding 2 M NaOH solution(Mallinckrodt Baker). Separate solutions of aluminum nitrate andmagnesium nitrate were prepared as follows: 27.5 g of aluminum nitrate(Al(NO₃)₃.9H₂O (EMD Sciences, AX0705-11)) was dissolved in 100 ml ofwater, and 57.6 g of magnesium nitrate (Mg(NO₃)₂.6H₂O (EMD Sciences,MX0060-1)) was dissolved in 100 ml of water. The two solutions wereadded drop-wise and concurrently to the preheated solution containingEDTA and nickel. The time for this addition was about 45 minutes. Duringthis addition, sodium hydroxide solution was added to maintain a pH ofabout 10. The preheated solution was stirred during the addition of themetal nitrates. After complete addition of these metal nitrates, thesuspension was kept at 65° C. with stirring for 1 hour and then aged atthis temperature for 18 hours without stirring. The precipitate wasseparated from solution by filtering. The synthesized separated solidswere dried in vacuum oven at 90° C. for 48 hours and calcined at 360° C.for 2 hours in nitrogen. The heating protocol was as follows: theprecipitate was placed in a 1 inch (2.5 cm) diameter tube furnace, andthe temperature was increased from 25° C. to 360° C. at 2.4° C. perminute over the course of 140 minutes, followed by 360° C. for 2 hours.The catalyst was evaluated according to the procedure described inExample 1. Results are shown in Table 2.

TABLE 2 Temp. EtOH i-BuOH ° C. Minutes Conv. Sel. 300 60 54.9 6.9 350 6079.2 9.2 400 60 84.5 12.3

Example 3 [M²⁺ _(1−x)M³⁺ _(x)(OH)₂][{(M′A′)^(n′−)}_(a)A^(n−)_((1−a)(n′/n))]_(x/n′).yH₂O M²⁺ is Mg; M³⁺ is Al; x=0.25; a=0.10; A′=theanion of ethylenediaminetetraacetic acid; M′=Ni; A^(n−)=OH⁻; n′=2; n=1

The procedure used for the synthesis of the hydrotalcite in Example 1was followed, except that 1.07 grams of nickel nitrate hexahydrate wasused in place of cobalt nitrate. The catalyst was evaluated according tothe procedure described in Example 1. Results are shown in Table 3.

TABLE 3 Temp. EtOH i-BuOH ° C. Minutes Conv. Sel. 300 60 66.3 7.6 350 6080.1 9.6 400 60 86.5 9.5

Example 4 [M²⁺ _(1−x)M³⁺ _(x)(OH)₂][{(M′A′)^(n′−)}_(a)A^(n−)_((1−a)(n′/n))]_(x/n′).yH₂O M²⁺ is Mg; M³⁺ is Al; x=0.25; a=0.10; A′=theanion of ethylenediaminetetraacetic acid; M′=Ni; A^(n−)=OH⁻; n′=2; n=1

The procedure used for the synthesis of the hydrotalcite in Example 1was followed, except that 0.11 grams of nickel nitrate hexahydrate wasused in place of cobalt nitrate. The catalyst was evaluated according tothe procedure described in Example 1. Results are shown in Table 4.

TABLE 4 Temp. EtOH i-BuOH ° C. Minutes Conv. Sel. 300 60 58.0 6.4 350 6076.1 9.4 400 60 85.5 10.7

Example 5 [M²⁺ _(1−x)M³⁺ _(x)(OH)₂][{(M′A′)^(n′−)}_(a)A^(n−)_((1−a)(n′/n))]_(x/n′).yH₂O M²⁺ is Mg; M³⁺ is Al; x=0.25; a=0.10; A′=theanion of ethylenediaminetetraacetic acid; M′=Co; A^(n−)=OH⁻; n′=2; n=1

The procedure used for the synthesis of the hydrotalcite in Example 1was followed, except that 0.11 grams of cobalt nitrate hexahydrate wasused. The catalyst was evaluated according to the procedure described inExample 1. Results are shown in Table 5.

TABLE 5 Temp. EtOH i-BuOH ° C. Minutes Conv. Sel. 300 60 60.6 4.5 350 6059.4 3.9 400 60 72.0 6.3

Example 6 [M²⁺ _(1−x)M³⁺ _(x)(OH)₂][{(M′A′)^(n′−)}_(a)A^(n−)_((1−a)(n′/n))]_(x/n′).yH₂O M²⁺ is Mg; M³⁺ is Al; x=0.25; a=0.10; A′=theanion of ethylenediaminetetraacetic acid; M′=Co; A^(n−)=OH⁻; n′=2; n=1

The procedure used for the synthesis of the hydrotalcite in Example 1was followed, except that 1.07 grams of cobalt nitrate hexahydrate wasused. The catalyst was evaluated according to the procedure described inExample 1. Results are shown in Table 6.

TABLE 6 Temp. EtOH i-BuOH ° C. Minutes Conv. Sel. 300 60 52.5 4.7 350 6066.4 4.9 400 60 84.6 6.1

Example 7 [M²⁺ _(1−x)M³⁺ _(x)(OH)₂][{(M′A′)^(n′−)}_(a)A^(n−)_((1−a)(n′/n))]_(x/n′).yH₂O M²⁺ is Mg; M³⁺ is Al; x=0.25; a=0.10; A′=theanion of ethylenediaminetetraacetic acid; M′=Cr; A^(n−)=OH⁻; n′=2; n=1

The procedure used for the synthesis of the hydrotalcite in Example 1was followed, except that 6.45 grams of chromium nitrate hexahydrate(Cr(NO₃)₃.9H₂O, Sigma-Aldrich) was used in place of cobalt nitrate. Thecatalyst was evaluated according to the procedure described inExample 1. Results are shown in Table 7.

TABLE 7 Temp. EtOH i-BuOH ° C. Minutes Conv. Sel. 300 60 39.8 5.6 350 6045.0 8.3 400 60 69.0 13.9

Example 8 [M²⁺ _(1−x)M³⁺ _(x)(OH)₂][{(M′A′)^(n′−)}_(a)A^(n−)_((1−a)(n′/n))]_(x/n′).yH₂O M²⁺ is Mg; M³⁺ is Al; x=0.25; a=0.10; A′=theanion of ethylenediaminetetraacetic acid; M′=Pt; A^(n−)=OH⁻; n′=2; n=1

The procedure used for the synthesis of the hydrotalcite in Example 1was followed, except that 0.1 grams of platinum dichloride (Alfa Aesar,Ward Hill, Mass.) was used in place of cobalt nitrate. The catalyst wasevaluated according to the procedure described in Example 1. Results areshown in Table 8.

TABLE 8 Temp. EtOH i-BuOH ° C. Minutes Conv. Sel. 300 60 76.6 13.4 35060 88.3 11.6 400 60 91.7 8.3

1. A process for making an isobutanol-containing product, comprising:contacting a reactant comprising ethanol and methanol with a catalyst ata reaction temperature and pressure sufficient to produce said reactionproduct, wherein said catalyst is derived from a hydrotalcite of theformula:[M²⁺ _(1−x)M³⁺ _(x)(OH)₂][{(M′A′)^(n′−}) _(a)A^(n−)_((1−a)(n′/n)]x/n′.y)H₂O wherein M²⁺ is divalent Mg, or a combination ofdivalent Mg and at least one divalent member selected from the groupconsisting of Zn, Ni, Pd, Pt, Co, Fe, and Cu; M³⁺ is trivalent Al, or acombination of trivalent Al and at least one trivalent member selectedfrom the group consisting of Fe and Cr; x is 0.66 to 0.1; M′ is (i) oneor more divalent members selected from the group consisting of Zn, Ni,Pd, Pt, Fe, Co, and Cu; or (ii) one or more trivalent members selectedfrom the group consisting of Fe, Cr, and Ru; or (iii) a mixture of oneor more of said divalent members with one or more of said trivalentmembers; A′ is an anion of ethylenediaminetetraacetic acid; n′ isabsolute value of a sum of an oxidation state of M′ and (−4); providedthat if M′ is said mixture, then n′ is calculated according to thefollowing equation:n′=an absolute value of [X_(D)(2)+X_(D)(−4)+X_(T)(3)+X_(T)(−4)], whereinX_(D)=a sum of a number of moles of all divalent members divided by (asum of a number of moles of all divalent members+a sum of a number ofmoles of all trivalent members), and X_(T)=a sum of the number of molesof all trivalent members divided by (the sum of the number of moles ofall divalent members+the sum of the number of moles of all trivalentmembers); A^(n−) is CO₃ ²⁻ with n=2 or OH⁻ with n=1; a=0.001 to 1; andy=0 to 4; wherein the hydrotalcite catalyst is partially decomposed. 2.The process of claim 1, wherein the decomposition is achieved by heatingfor a time and at a temperature sufficient to cause a diminution in thehydrotalcite powder X-ray diffraction pattern peak intensities between2θ angles of 10 degrees and 70 degrees using CuKα radiation.
 3. Theprocess of claim 1, wherein M²⁺ is Mg.
 4. The process of claim 1,wherein M³⁺ is Al.
 5. The process of claim 1, wherein M′ is Co.
 6. Theprocess of claim 1, wherein M′ is Ni.
 7. The process of claim 1, whereinM′ is Cr.
 8. The process of claim 1, wherein M′ is Pt.
 9. The process ofclaim 1, wherein A^(n−) is OH.
 10. The process of claim 1, wherein M²⁺is Mg; M³⁺ is Al; x is 0.25; a is 0.44; A′ is the anion ofethylenediaminetetraacetic acid; M′ is Co; A^(n−) is OH⁻; n′ is 2; nis
 1. 11. The process of claim 1, wherein M²⁺ is Mg; M³⁺ is Al; x is0.25; a is 0.44; A′ is the anion of ethylenediaminetetraacetic acid; M′is Ni; A^(n−) is OH⁻; n′ is 2; n is
 1. 12. The process of claim 1,wherein M²⁺ is Mg; M³⁺ is Al; x is 0.25; a is 0.10; A′ is the anion ofethylenediaminetetraacetic acid; M′ is Ni; A^(n−) is OH⁻; n′ is 2; nis
 1. 13. The process of claim 1, wherein said reaction temperature isfrom about 200° C. to about 500° C., and said pressure is from about 0.1MPa to about 20.7 MPa.